Known methods for generating pressure waves in airflows use the periodic connection of air domains at different pressures: pressure of the suction airflow in the pipeline with atmospheric pressure.
The idea of the use of periodic connection of the suction flow with the atmosphere—modulation of the suction flow, leads to an increase of the energy efficiency of the surface cleaning process using vacuum cleaning systems (U.S. Pat. No. 5,593,252, 1997). The further development of this idea extends the possibilities of application of more efficient energy modulated flows in a variety of technologies (U.S. Pat. No. 6,827,528, 2004). These include technologies using the surface modulated flows—above and underground apparatuses, airplanes etc., and volumetric modulated flows—transportation of fluid media through suction and discharge pipelines.
The use of an asymmetric drop-shaped form of the law of pressure change of the modulated waves (U.S. Pat. No. 8,573,896, 2013) allows it to significantly expand the potentialities of the applications of modulated flows and to increase the energy efficiency of the processes of pipeline transportation of one and multiphasic media with different physical properties (density, viscosity and heat conductivity), of filtering processes, of heat exchange processes; the improving oil recovery from the oil saturated stratum and others.
The increase of energy efficiency of all of the above mentioned possible applications of modulated flows in various technological processes are directly related to physical phenomena caused by the interaction of modulated pressure waves with given parameters, with the flow turbulence of the transporting medium, with the filtration system, with capillary porous medium of saturated stratum, for example. Additionally, parameters of these modulated pressure waves (amplitude, frequency, and law) are unambiguous, for each technological process and determine its energy efficiency. For example, the use of modulated pressure waves in the process of increasing oil production from the saturated stratum requires a larger value of the amplitude and a smaller value of the ratio of the front time TF(oil) to the period of generated waves T(oil), TF(oil)/T(oil), than in the process of pipeline transportation of water, (TF(oil)/T(oil))<<(TF(water)/T(water)). Moreover, the periods, frequencies, and laws (waveform) of pressure waves for these processes are different.
In all of the above noted technological processes there is given an affirmation of the consequences of the interaction between pressure waves and the given material medium, filter system or heat exchange surface. In those processes there already is assumed that the generated modulated pressure waves have the specified parameters (waveform), corresponding to the given process. No dependence of the physical properties of fluid: density, viscosity, and compressibility and values of over pressure and under pressure of are taken into account.
However, in spite of the quite diverse possible industrial applications of modulated pressure waves to reduce energy consumption in energy-intensive technological processes, there is presently no proper method of generating pressure waves with predetermined parameters of waveform for the given parameters of a technological process.